The present invention relates to an image display apparatus, an image display method and a magnetic resonance imaging apparatus. The present invention relates particularly to an image display apparatus, an image display method and a magnetic resonance imaging apparatus, each of which displays a form image indicative of a form about an imaging area of a subject, and a quantitative value image indicative of quantitative values measured with respect to characteristics of the imaging area.
An image display apparatus for a magnetic resonance imaging (MRI) apparatus or the like displays an image of a subject and has frequently be used for medical applications, in particular.
In the magnetic resonance imaging apparatus, an imaging area of a subject is accommodated in an imaging space formed with a static magnetic field thereby to arrange spins of proton in the imaging area in the direction in which the static magnetic field is formed, and a magnetization vector thereof is produced. An RF pulse having a resonant frequency is applied to generate a nuclear magnetic resonance (NMR) phenomenon, thereby flipping the spins and changing the magnetization vector of the proton. Thereafter, the magnetic resonance imaging apparatus receives magnetic resonance (MR) signals produced when the proton is returned to the original state of magnetization vector. Based on the received magnetic resonance signals, a form image indicative of the form of the imaging area, a quantitative image indicative of the characteristics of the imaging area, etc. are produced and displayed.
Described specifically, each of slice images indicative of tissues such as organs is displayed as a form image with respect to a slice plane of the subject. As to an MRA image indicative of the velocity of flow of blood or the like flowing into the blood vessels of the subject, a phase image obtained by a phase contrast method, an ADC (Apparent Diffusion Coefficient) map formed as a diffusion image or the like is displayed as a quantitative image indicative of quantitative values obtained by measuring characteristics in the subject (refer to, for example, a patent document 1).    Patent Document 1. Japanese Unexamined Patent Publication No. 2000-60821.
After a specific area like, for example, a region of interest is set at the quantitative image by an operator, quantitative values measured with respect to the specific area are produced as a quantitative value image expressed in figures from pixel values about the set specific area. Then, the quantitative value image is displayed on a display screen side by side with the quantitative image such as the ADC map. Thus, a quantitative image diagnosis can be effected on the specific area.
Since, however, form information indicative of the position of a form of each tissue such as an organ may not be displayed sufficiently with respect to the quantitative image such as the ADC map, there is a case in which checking a tissue targeted for diagnosis and a quantitative value about the tissue against each other is difficult. That is, since there is a case in which it is difficult to accurately grasp the position of the tissue targeted for diagnosis at the quantitative image, there is a case where accurately grasping the quantitative value of the characteristic of the tissue is difficult.
Therefore, the operation of switching the display to the quantitative image again after the form image indicative of the form of each tissue is displayed to grasp and the position of the tissue, and specifying the tissue's position at the quantitative image is executed. Thus, it was necessary to perform a cumbersome operation.
When the centers of FOVs (Fields Of View) of the form image and the quantitative image are placed in their corresponding positions different from each other, it was difficult to compare the positions of the tissues of the two to each other and specify the same even when the above operation was carried out.
Thus, since it is not easy to accurately specify the position of each tissue targeted for diagnosis upon quantitatively diagnosing the target for diagnosis, there was a case in which improving diagnostic efficiency was difficult.